>>That was just the bays…three 144-point Switchcraft TT bays >>with 20-foot tails on every position. All soldered, no punchblocks. >>I had wire strung all over my store. I was using three colors >>(red, black, and blue) and it actually looked kind of festive. >>Took forever.

>Speaking of cable, I ran across something last week >which was new to me: conductive “insulation”. In the >process of minimizing the cable situation on my >pedalboard, I had cut a pre-made 3′ Peavey cable in >half and made it into two 1.5′ cables using some >solderless straight .25″ connectors. I checked the >connections using the “audible short” function on my >meter, and everything was fine. Two hours later at >practice, I had almost no signal from the pedalboard >to the amp, so I started bypassing effects and swapping >cables until I had a good signal with at least my >Fulldrive II & DejaVibe. In troubleshooting the problem >later, I found that both of the smaller cables I’d made >had high-resistance shorts between the shield and center >conductor. Turns out that the black sleeve between the >braid & center conductor insulation was conductive, >and was barely making contact with a *single* wire from >the center conductors on each cable. I’ll admit to not >having done much cable-building in the past couple of >years, but this is the first time I’ve run across this. >Is it common with good cable nowadays, or mostly with >cheaper stuff?

Lord Valve Speaketh: Actually, it’s the *good* stuff that has that. The “conductive insulation” you ran across isn’t insulation, it’s electrostatic shielding. This can be plastic or cloth based; Canare cable uses plastic and Belden uses cloth. It’s there to reduce mechanically generated noises; high-impedance cable can be quite microphonic, and can also make scritchy-scratchy noises when it’s slithered around on the floor. This is due to random “stray” charges generated within the cable itself (like “static” electricity) and also to changes in cable capacitance as the wire flexes, slightly changing the distance between the outer shielding and the inner conductor. If you’re making your own cables and you encounter what appears to be an extra layer of “insulation” between the center conductor and the shield, take care to remove it from the exposed portion of the center conductor before you solder everything in place. If *any* of it touches the copper portion of the center conductor, you will have a high-resistance short from tip to sleeve; as you found out, using the low-ohms range on your meter to check from tip to sleeve will *not* detect this condition. What appeared to be a perfectly good cable when you were finished making it became a source of signal attenuation in the field. (BTW, this is *another* reason not to use “solderless” connectors; you cannot *see* the actual connections inside the plugs, and all kinds of bogus crud could be in there.) I learned early on that whenever I sell someone a piece of good- quality cable, I’ll either need to spend five minutes (now) telling the dude (or dude-ette) how to prepare it for soldering or spend ten minutes (later) listening to him/her bitch about the “shitty” cable I sold. For guys what rolls their own, here’s the best combo I’ve found: Canare GS-6 cable and Switchcraft 280 plugs. I know the temptation is to use the snazzy-looking Neutrik plugs; they are hard to solder to without a *really* powerful iron, and the strain relief system is bogus. They cost twice as much, too. Stick with the Switchcraft; they were good enough for Grampaw and they’re *still* the best. (I sell both kinds, in case anyone is wondering.) If you want to make a cable that is damn near indestructible, use a piece of 3/8″ HST over the inner part of the plug; fill the inner portion with hot-glue and slide the shrink over the glue while it’s still hot; it’ll begin to shrink immediately. Finish shrinking it with your heat- gun (or a 1000W Par-64 can, or a propane torch set on low, or a cigarette lighter, or a hot-air popcorn popper [all of which I have used successfully in the field]) and wait for it to cool before removing any glue that squished out the edges while you were shrinking it. This is the *best* termination system that I’ve been able to devise; I have guitar cables in the field that are still going strong after more than a decade of use. So Sayeth the Lord.

Lord Valve

VISIT MY WEBSITE: http://www.freeyellow.com/members2/lord-valve/ Good tube FAQ for newbies. Click the e-mail link and join my SPAM LIST; just put “SPAM ME” in the header and I’ll sign you up. (If you only want a set of e-mail catalogs, put “CATS ONLY” in the header.) I specialize in top quality HAND-SELECTED NOS and current-production vacuum tubes for guitar and bass amps. Good prices, fast service. TONS of gear and parts in stock…let’s DEAL!